Sometimes, distractions can be useful in themselves. That’s the message this week from the Planck space telescope, which has a mighty big mission: to take baby pictures of the universe. While it hasn’t yet accomplished that task, the preliminary disturbances that Planck scientists are now dealing with are yielding cosmic insights of their own.
Orbiting the Sun roughly 1.5 million kilometres from Earth, the Planck space-based telescope is scanning the sky for ultra-cold objects. Its instruments are chilled to just a tenth of a degree above absolute zero and are designed to pick up the faint microwave afterglow from the Big Bang, which scientists hope can tell them about the earliest moments of the Universe. [Nature News]
Planck was launched in spring of 2009 by the European Space Agency, and it’s still gathering data to complete its chart of this cosmic microwave background (CMB); researchers hope the map will shed light on the young universe’s brief “inflationary” period when it expanded extremely rapidly. At the moment, however, Planck is busy detecting other sources of microwaves so that it can subtract this “foreground” radiation from its map of the background.
So what are some of these sources?
Massive Galactic Clusters
Among the results announced this week was the discovery of more than 20 previously unknown galactic clusters–enormous groups of galaxies that are gravitationally bound to each other.
Studying the clusters could yield new insights into the evolution of galaxies, as well as the effects of dark matter and dark energy. The data from Planck confirm the view that galaxies form along a network of dense regions that spread across empty space like the threads of a spider web. “They sit in the knots of the cosmic web,” said Elena Pierpaoli, a Planck team member from the University of Southern California. [MSNBC]
A Fog in the Milky Way
Here in our own galaxy, Planck has examined the diffuse glow seen in dense and dusty regions; astronomers have known about this “anomalous microwave emission” for some time, but haven’t understood its source.
However, data collected across Planck’s unprecedented wide wavelength range confirm the theory that it is coming from dust grains set spinning at several tens of billion times a second by collisions with either fast-moving atoms or packets of ultraviolet light. This new understanding helps to remove this local microwave ‘fog’ from the Planck data with greater precision, leaving the cosmic microwave background untouched. [press release]
There’s plenty more–there are 25 papers in the first batch of scientific findings. As delightful as all these discoveries are, Planck scientist Jan Tauber reminds us that they’re actually just distractions from Planck’s main mission.
From the perspective of the CMB, these newly announced discoveries are actually noise. Scientists will have to eliminate these microwave sources and many others before they can reconstruct an unpolluted map of the CMB. “It’s a really juicy first taste of what’s to come,” says Tauber. [Nature News]
The satellite will continue to gather data through the end of 2011, and researchers hope to have the CMB map completed by January 2013.
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Image: ESA / HFI / LFI Consortia